Pareidolia’s an interesting phenomenon. It’s basically an effect wherein your brain detects a pattern where there isn’t one. For example, Phil Plait just posted the following on his Bad Astronomy blog.
Now, a lot of people, looking at that particular combination of light and shadow, see something like this.
And, after a suggestion by Dave R, this.
Why? Why does your brain do this? What’s the point? The thing is, visual information is very noisy. The fact that we can make any sense at all out of the photons plowing into our eye-holes is nothing short of amazing. And, from a survival characteristic point of view, seeing patterns where there are none is slightly less fatal than missing ones that are there. (Hmm, that jumble of earthtones bounding toward me is making a growling sound. I wonder if… ACK!)
Also, think about what you’re doing right now. You’re looking at an array of dots that are lit up in an arrangement that mimics a series of inscriptions on paper, which in turn represents a sequence of vocalizations to which humans have learned to ascribe meaning.
A lot of the mechanisms that your brain uses to wring some sort of meaning out of those blinking dots also cause you to see Jesus in a banana, or angry slippers, or Yoda in a cloud. It’s not such a bad trade-off, overall.